EP0032117A2 - Appareil de détection de trous ou défauts sur des surfaces - Google Patents

Appareil de détection de trous ou défauts sur des surfaces Download PDF

Info

Publication number
EP0032117A2
EP0032117A2 EP81100044A EP81100044A EP0032117A2 EP 0032117 A2 EP0032117 A2 EP 0032117A2 EP 81100044 A EP81100044 A EP 81100044A EP 81100044 A EP81100044 A EP 81100044A EP 0032117 A2 EP0032117 A2 EP 0032117A2
Authority
EP
European Patent Office
Prior art keywords
light
rows
mirrors
monitoring apparatus
accordance
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP81100044A
Other languages
German (de)
English (en)
Other versions
EP0032117A3 (en
EP0032117B1 (fr
Inventor
Erwin Sick
Dieter Dr. Röss
Siegfried Mankel
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Erwin Sick GmbH Optik Elektronik
Original Assignee
Erwin Sick GmbH Optik Elektronik
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Erwin Sick GmbH Optik Elektronik filed Critical Erwin Sick GmbH Optik Elektronik
Publication of EP0032117A2 publication Critical patent/EP0032117A2/fr
Publication of EP0032117A3 publication Critical patent/EP0032117A3/en
Application granted granted Critical
Publication of EP0032117B1 publication Critical patent/EP0032117B1/fr
Expired legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/89—Investigating the presence of flaws or contamination in moving material, e.g. running paper or textiles
    • G01N21/8901—Optical details; Scanning details
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques

Definitions

  • the present invention relates to monitoring apparatus and has particular reference to combined optical and electronic monitoring apparatus for detecting holes or surface defects in webs or other light reflecting surfaces.
  • the principal object underlying the present invention is to provide monitoring apparatus which is particularly compact and which can be readily manufactured. It is a further object of the present invention to provide an improved apparatus for detecting light remitted from the surface of a moving web of material.
  • the present invention envisages monitoring apparatus, in particular for monitoring for holes or surface defects in webs or other light reflecting surfaces, the apparatus comprising a light transmitting device including a laser light source for projecting a light curtain towards a surface under investigation; light receiving means for receiving light from said light curtain, after said light curtain has fallen on said surface, and for directing this light to photoelectric detection means and an electronic processing circuit for evaluating signals from said photoelectric detection means to signify the presence and/or nature of a defect in said surface; said light transmitting device comprising a plurality of inclined strip-like dividing mirrors arranged one behind the other in first and second rows in an alternating sequence, with the end regions of adjacent dividing mirrors of the sequence overlapping in the direction of the rows, and means for scanning light from said laser light source to form first and second scanning light beams which are incident on respective ones of said rows in the directions of these rows and which are deflected through substantially 90° by said dividing mirrors to form said light curtain; said light receiving means comprising a plurality of light gathering devices associated
  • This arrangement is particularly compact because all the components can be located in a common housing on one side of the web.
  • the use of a plurality of inclined strip-like dividing mirrors arranged one behind the other in first and second rows in an alternating sequence with the end regions of adjacent dividing mirrors of the sequence overlapping in the direction of the rows enables a very broad light curtain to be generated without gaps.
  • the depth of the housing containing the monitoring apparatus can be kept relatively small for a given width of the scanning light curtain simply by increasing the number of strip-like dividing mirrors.
  • the light gathering devices can readily be arranged closely adjacent the first and second rows of dividing mirrors so that the overall width of the housing can also be kept relatively small.
  • a cylindrical lens common to both the first and second rows of dividing mirrors and the first and second rows of light gathering devices extends between said rows and said surface under investigation with the focal line of said cylindrical lens lying on said surface.
  • a single cylindrical lens is thus advantageously used for both the light beams transmitted towards the surface under investigation from the first and second rows of strip-like dividing mirrors and for the light remitted from the surface under investigation to the light gathering devices.
  • the monitoring apparatus can also be used with advantage in an arrangement in which the surface under investigation takes the form of a web guided over the surface of a drum the axis of which lies parallel to the rows of dividing mirrors and light gathering devices and in the plane of symmetry of the apparatus.
  • the radius of the drum should preferably be chosen so that the transmitted light beams, following reflection at the angular of specular reflection on the surface of the drum,impinge centrally on the associated light gathering devices. In this way it is possible to ensure that specular reflection occurs into both the first and second rows of light gathering device which are spaced apart to either side of the central plane of symmetry.
  • An especially preferred light transmitter which is compactly arranged and of simple construction, features an arrangement in which a light beam from said laser light source is split into first and second light beams via a beam divider and a deflecting mirror arranged parallel thereto,with said first and second light beams converging on a mirror wheel arranged symmetrically at the focal point of two strip-like concave mirrors which are aligned with said first and second rows of dividing mirrors whereby said first and second scanning light beams are generated in the image spaces of said strip-like concave mirrors.
  • the individual dividing mirrors of the first and second rows are transversely spaced apart from one another.
  • This arrangement brings particular constructional advantages without disadvantageously affecting the optical quality of the apparatus.
  • the transverse spacing between the individual mirrors advantageously amounts to approximately twice their width.
  • a particularly preferred embodiment which is primarily intended for monitoring for holes : makes use of light gathering devices in the form of first and second rows of light conducting rods which replace the strip-like Fresnel lenses and which each carry a photoelectric converter at at least one end face. All the photoelectric converters are once again preferably connected to a common electronic processing circuit.
  • the present invention makes use of numerous small light conducting rods which are arranged in first and second rows and displaced in the longitudinal direction in order to obtain a continuous scanning range without gaps.
  • the light conducting rods preferably overlap in the longitudinal direction by an amount in the range from 2 to 30 %,and particularly by 15 %,of their lengths. I.e. the amount of overlap of one light conducting rod on the next adjacent conducting rod lies in the aforementioned range.
  • a common cylindrical lens can once again be associated with all the light conducting rods whereby the constructional complexity can be significantly reduced without disadvantageously reducing the optical quality of the apparatus.
  • the light gathering devices of the first and second rows can likewise be transversely spaced apart by an amount which preferably corresponds to their widths so that the mounting of the individual devices and their connection to the electronic processing circuit is possible in a straightforward manner.
  • a laser light source 30 is arranged above a housing 13 parallel to the direction of scanning.
  • the laser light source directs a sharply defined light beam 2 to a partially transmitting mirror or beam divider 21 which is also illustrated in Fig. 2.
  • the beam divider 21 splits the light beam 2 into first and second light beams 2', 2" with intensities in the ratio 1 : 1.
  • the second light beam 2" which is deflected at the surface of the beam divider 21 is once again deflected by a plane deflecting mirror 22 into the same direction as the first light beam 2' which is transmitted by the beam divider 21.
  • the plane mirror 22 is so arranged that the first and second light beams 2', 2" converge slightly on one another so that they meet on the surface of a mirror wheel 23 after further deflection at a further plane deflecting mirror 31.
  • the mirror wheel generates first and second slightly divergent scanning light beams 32, 33 which impinge parallel to the direction of the laser 30 on two strip-like plane mirrors 24', 25' which are spaced apart sideways from each other.
  • the first and second light beams 2', 2" extend at right angles to the scanning direction of the apparatus between the deflecting mirror 31 and the mirror wheel 23.
  • the strip-like plane mirrors 24', 25' reflect the incident scanning light beams 32, 33 to strip-like concave mirrors 24, 25.
  • the optical arrangement is such that the mirror wheel sits at the focal point of these two concave mirrors.
  • first and second scanning light beams 34, 35 emerge from the two concave mirrors 24, 25 with these light beams executing a parallel scanning movement in which they are continuously displaced parallel to themselves through the image spaces of their respective concave mirrors.
  • These scanning light beams fall on respective first and second rows of strip-like dividing mirrors which are inclined at 45 0 to the incident scanning light beams.
  • the dividing mirrors 9 and 10 are arranged one behind the other in first and second rows in an alternating sequence with the end regions of adjacent dividing mirrors of the sequence overlapping in the direction of the rows.
  • the scanning light beam 34 passes through all the mirrors 9 of the first row whereas the scanning light beam 35 passes through all the dividing mirrors of the second row 10.
  • the reflectivity of the dividing mirrors of each of the rows progressively increases in accordance with a simple mathematical progression along the row so that the same fraction of the light beam is reflected into the light curtain region by each successive dividing mirror of the row.
  • the last mirror of each row can be a fully reflecting mirror instead of a dividing mirror.
  • the inclined dividing mirrors thus reflect the incident scanning light beams through substantially 90° and form a series of overlapping light curtains which can be used to scan-across the full width of a web.
  • the downwardly deflected scanning light beams 34, 35 impinge on a cylindrical lens 18 which extends over the whole length of the first and second rows of inclined mirrors.
  • the cylindrical lens 18 projects the scanning light beams which form the light curtain to two adjacent positions 26, 26' on the surface of a material web 17 which is under investigation.
  • This material web is tensioned over the surface of a drum 19 which is rotatable about an axis 20 which extends parallel to the first and second rows of inclined mirrors 9, 10 and lies in the central plane of symmetry 36 of the apparatus.
  • the scanning positions 26, 26' are spaced from the cylindrical lens 18 by a distance equivalent to its focal length.
  • the inclined mirror strips 9, 10 are transversely spaced apart from each other in the first and second rows by a distance A which is approximately twice as large as their widths.
  • the cylindrical lens 18 symmetrically straddles the vertical central plane 36 between the two rows of inclined mirror strips 9, 10.
  • the cylindrical lens extends on both sides significantly beyond the scanning light beams of the light curtain so that the outer regions of the cylindrical 'lens can be used for the reception of light reflected or remitted from the surface of the web 17.
  • Fresnel lenses which are displaced in their longitudinal directions are arranged in two rows above the outer regions of the cylindrical lens 18. These Fresnel lenses cooperate with the cylindrical lens 18 and further cylindrical lenses 37 to concentrate the received light on photoelectric detectors 7 which are associated one with each of the Fresnel lenses.
  • a single photoelectric detector or converter 7 and a single cylindrical lens 37 are shown on one side of the central plane of symmetry 36.
  • a similar multiple arrangement of photoconductors 7 and cylindrical lenses 37 displaced in the longitudinal direction of the rows of Fresnel lenses will be understood to be present on the other side of the central plane of symmetry 36.
  • the radius r of the drum 19 is so chosen that the light beams falling onto the surface of the web 17 at the points 26, 26' pass through the outer regions of the cylindrical lens 18 and are deflected into the Fresnel lenses 5, 6 when specular reflection occurs at the surface of the web 17.
  • This arrangement is thus particularly suitable for investigating metal surfaces to detect the presence of surface defects.
  • the compact nature of the arrangement can be readily appreciated by having regard to Fig. 4 from which it can be seen that the first and second rows of Fresnel lenses and the associated photoelectric detectors 7 can be arranged closely alongside the first and second rows of dividing mirrors 9, 10. To achieve a compact arrangement it is merely necessary to pay careful attention to the optical geometry of the apparatus.
  • Fig. 5 shows an analogous arrangement in which the Fresnel lenses are replaced by small light conducting rods 5', 6' with the light conducting rods being displaced in the longitudinal direction and arranged in first and second rows in an alternating sequence.
  • This alternating sequence can be best seen by reference to Fig. 6.
  • the arrangement is here however used not to determine faults in the surface of a web which manifest themselves by reflection but rather to detect holes in the surface of the web which manifest themselves in transmission.
  • the light receiving device is arranged on the opposite side of the web from the light transmitting device. As seen in Figs.
  • cylindrical lenses 28, 28', 29, 29' are provided both in front of the material web and behind the material web with these cylindrical lenses extending over the full lengths of the respectively associated first and second rows of light conducting rods and strip-like dividing mirrors.
  • the cylindrical lens 28 concentrates the light curtain from the row of inclined mirrors 10 onto the surface of the web 17 and light passing through holes in the web falls on the second cylindrical lens 29 which then concentrates this light in the interior of the light conducting rods 6'.
  • the second pair of cylindrical lenses 28', 29' function in the same manner.
  • the light conducting rods each have a stepped mirror arrangement 39 arranged along their surface facing the light entry surface.
  • the individual mirrors of the stepped mirror arrangement serve to direct all incident light at angles of total reflection into the interior of the rod so that this light reaches a photoelectric detector 7 arranged at at least one end face of the light conducting rod. As seen in Fig. 6 all the photoelectric converters 7 are connected to a common electronic processing circuit 8.
  • all the light conducting rods 5', 6' lying within one row are simultaneously able to receive light from the light curtain.
  • the different signalsreceived from the individual light conducting rods can be evaluated in the electronic processing circuit 8 and can be used to provide an indication of the location of the fault in the web.
  • the present embodiment uses five light conducting rods spaced apart across the web so that five different detectors are connected to the electronic processing circuit.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Textile Engineering (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Materials By The Use Of Optical Means Adapted For Particular Applications (AREA)
EP81100044A 1980-01-07 1981-01-07 Appareil de détection de trous ou défauts sur des surfaces Expired EP0032117B1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE3000352 1980-01-07
DE3000352A DE3000352C2 (de) 1980-01-07 1980-01-07 Optoelektronisches Überwachungsgerät

Publications (3)

Publication Number Publication Date
EP0032117A2 true EP0032117A2 (fr) 1981-07-15
EP0032117A3 EP0032117A3 (en) 1982-05-12
EP0032117B1 EP0032117B1 (fr) 1985-05-02

Family

ID=6091616

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81100044A Expired EP0032117B1 (fr) 1980-01-07 1981-01-07 Appareil de détection de trous ou défauts sur des surfaces

Country Status (3)

Country Link
US (1) US4431309A (fr)
EP (1) EP0032117B1 (fr)
DE (1) DE3000352C2 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2255650A (en) * 1991-05-08 1992-11-11 Spectra Physics Scanning Syst Laser bar code scanner producing parallel scan lines
CN108489386A (zh) * 2018-03-23 2018-09-04 福建农林大学 一种基于光电幕墙的毛边锯材形状位姿识别方法
CN111750777A (zh) * 2020-06-22 2020-10-09 华中农业大学 自走式作物表型高通量检测装置
CN112666168A (zh) * 2020-12-29 2021-04-16 尚越光电科技股份有限公司 一种cigs电池片不锈钢基底卷对卷表面快速检测系统

Families Citing this family (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3125189C2 (de) * 1981-06-26 1984-06-14 Erwin Sick Gmbh Optik-Elektronik, 7808 Waldkirch Fehlersuchgerät für breite Bahnen
US4570074A (en) * 1982-09-29 1986-02-11 Q-Val Incorporated Flying spot scanner system
DE3635271C1 (de) * 1986-10-16 1987-10-29 Sick Optik Elektronik Erwin Lichtvorhangsvorrichtung
DE3806385A1 (de) * 1988-02-29 1989-09-07 Feldmuehle Ag Verfahren und vorrichtung zum pruefen von transparenten bahnen
US5068523A (en) * 1990-03-02 1991-11-26 Intec Corp. Scanner detector array and light diffuser
US5404008A (en) * 1993-07-16 1995-04-04 Rockwell International Corporation Control system for detecting intrusion of a light curtain
US5861078A (en) * 1993-08-12 1999-01-19 Cmd Corporation Method and apparatus for detecting a seal on a plastic bag
US5488480A (en) * 1994-02-16 1996-01-30 Cmd Corporation Apparatus and method for detecting a heat seal in a moving plastic film
US5539198A (en) * 1993-09-28 1996-07-23 Rockwell International Corporation Uniform sensitivity light curtain
US5985187A (en) 1997-09-10 1999-11-16 Southpac Trust International, Inc. Apparatus and method for forming an article
US6354716B1 (en) 2000-08-04 2002-03-12 Honeywell International Inc Light curtain device
KR102048361B1 (ko) * 2013-02-28 2019-11-25 엘지전자 주식회사 거리 검출 장치, 및 이를 구비하는 영상처리장치
DE102014011268A1 (de) * 2014-07-29 2016-02-04 Brückner Maschinenbau GmbH & Co. KG Optische Fehlstellendetektion

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE6601847U (de) * 1963-10-04 1969-04-10 Erwin Sick Photoelektrische abtastvorrichtung fuer durchlaufende materialbahnen
DE2255788A1 (de) * 1972-11-15 1974-05-16 Peter Hans Schutz von objekten (anlagen und gelaende) gegen unbefugtes eindringen mittels laser-verfahren
US3821557A (en) * 1972-03-10 1974-06-28 P Lipke Device for checking movable webs of paper synthetic material metal foils and the like
US3931525A (en) * 1972-09-21 1976-01-06 Ferranti, Limited Detection of blemishes in surfaces
DE2532602A1 (de) * 1975-07-21 1977-01-27 Sick Optik Elektronik Erwin Optische vorrichtung zur verbreiterung eines lichtvorhanges
US4013367A (en) * 1974-05-13 1977-03-22 Tokyo Shibaura Electric Co., Ltd. Apparatus for detecting irregularities in the surfaces of materials
DE2532603B2 (de) * 1975-07-21 1978-04-13 Erwin Sick Gmbh Optik-Elektronik, 7808 Waldkirch Optische Vorrichtung zur Bestimmung des Lichtaustrittswinkels
DE2808359B2 (de) * 1978-02-27 1979-12-20 Erwin Sick Gmbh Optik-Elektronik, 7808 Waldkirch Suchgerät für Löcher in Bahnen

Family Cites Families (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DD54409A (fr) *
US2547623A (en) * 1948-12-27 1951-04-03 Gen Electric Spot detector recorder
US3760184A (en) * 1972-03-10 1973-09-18 Sick Erwin Fa Photoelectric monitoring device for pluralities of threads
DE2433683C3 (de) * 1974-07-12 1979-02-22 Erwin Sick Gmbh Optik-Elektronik, 7808 Waldkirch Vorrichtung zur Überwachung einer Materialbahn auf Fehlstellen
DE2508366C3 (de) * 1975-02-26 1979-05-17 Erwin Sick Gmbh Optik-Elektronik, 7808 Waldkirch Optische Vorrichtung mit einem Lichtvorhang
JPS5849819B2 (ja) * 1975-03-18 1983-11-07 コニカ株式会社 ソウサシキケンサソウチ
US4040745A (en) * 1975-06-30 1977-08-09 International Business Machines Corporation Inspection tool
DE2550815C3 (de) * 1975-11-12 1979-05-31 Erwin Sick Gmbh Optik-Elektronik, 7808 Waldkirch Optisches Abtastsystem
CH608628A5 (fr) * 1975-11-21 1979-01-15 Sick Optik Elektronik Erwin
DE2602970C3 (de) * 1976-01-27 1979-02-08 Erwin Sick Gmbh Optik-Elektronik, 7808 Waldkirch Vorrichtung zur Überwachung einer Materialbahn auf Fehlstellen
US4038554A (en) * 1976-03-09 1977-07-26 Columbia Research Corporation Detection of flaws in a moving web of transparent material
CH600301A5 (fr) * 1976-05-28 1978-06-15 Bbc Brown Boveri & Cie
DE2727926C3 (de) * 1977-06-21 1980-11-13 Erwin Sick Gmbh Optik-Elektronik, 7808 Waldkirch Vorrichtung zur Ermittlung von Fehlstellen auf der reflektierenden Oberfläche einer Bahn
DE2808360C3 (de) * 1978-02-27 1981-09-24 Erwin Sick Gmbh Optik-Elektronik, 7808 Waldkirch Optische Vorrichtung zur Bestimmung des Lichtaustrittswinkels
US4260899A (en) * 1979-06-14 1981-04-07 Intec Corporation Wide web laser scanner flaw detection method and apparatus
US4310250A (en) * 1980-02-01 1982-01-12 Erwin Sick Gmbh Apparatus for monitoring for faults in translucent strip material

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE6601847U (de) * 1963-10-04 1969-04-10 Erwin Sick Photoelektrische abtastvorrichtung fuer durchlaufende materialbahnen
US3821557A (en) * 1972-03-10 1974-06-28 P Lipke Device for checking movable webs of paper synthetic material metal foils and the like
US3931525A (en) * 1972-09-21 1976-01-06 Ferranti, Limited Detection of blemishes in surfaces
DE2255788A1 (de) * 1972-11-15 1974-05-16 Peter Hans Schutz von objekten (anlagen und gelaende) gegen unbefugtes eindringen mittels laser-verfahren
US4013367A (en) * 1974-05-13 1977-03-22 Tokyo Shibaura Electric Co., Ltd. Apparatus for detecting irregularities in the surfaces of materials
DE2532602A1 (de) * 1975-07-21 1977-01-27 Sick Optik Elektronik Erwin Optische vorrichtung zur verbreiterung eines lichtvorhanges
DE2532603B2 (de) * 1975-07-21 1978-04-13 Erwin Sick Gmbh Optik-Elektronik, 7808 Waldkirch Optische Vorrichtung zur Bestimmung des Lichtaustrittswinkels
DE2808359B2 (de) * 1978-02-27 1979-12-20 Erwin Sick Gmbh Optik-Elektronik, 7808 Waldkirch Suchgerät für Löcher in Bahnen

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
LASER + ELEKTRO-OPTIK, No. 6, 1973 Stuttgart G. PINIOR "Oberfl{chenkontrolle mit Laser" pages 13 to 14 *

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2255650A (en) * 1991-05-08 1992-11-11 Spectra Physics Scanning Syst Laser bar code scanner producing parallel scan lines
CN108489386A (zh) * 2018-03-23 2018-09-04 福建农林大学 一种基于光电幕墙的毛边锯材形状位姿识别方法
CN111750777A (zh) * 2020-06-22 2020-10-09 华中农业大学 自走式作物表型高通量检测装置
CN112666168A (zh) * 2020-12-29 2021-04-16 尚越光电科技股份有限公司 一种cigs电池片不锈钢基底卷对卷表面快速检测系统
CN112666168B (zh) * 2020-12-29 2022-08-05 尚越光电科技股份有限公司 一种cigs电池片不锈钢基底卷对卷表面快速检测系统

Also Published As

Publication number Publication date
DE3000352C2 (de) 1986-07-24
EP0032117A3 (en) 1982-05-12
DE3000352A1 (de) 1981-09-24
EP0032117B1 (fr) 1985-05-02
US4431309A (en) 1984-02-14

Similar Documents

Publication Publication Date Title
US4431309A (en) Monitoring apparatus
US4511803A (en) Fault detection apparatus for material webs
US4402609A (en) Light curtain apparatus
US4302105A (en) Detection apparatus for finding holes in webs
US4127771A (en) Optical apparatus
US4004152A (en) Apparatus for monitoring a moving web of material for faults
US4559451A (en) Apparatus for determining with high resolution the position of edges of a web
EP0099023B1 (fr) Tête de mesure pour la mesure de réflexion
US4306813A (en) Apparatus for determining faults in strip material
US4904877A (en) Optical scanning apparatus for detecting faults in transparent material wherein the plane of incident light is arranged at the breuster angle to the normal to the surface
EP0182471B1 (fr) Appareil d'inspection utilisant un balayage par un faisceau de rayonnement
US4085322A (en) Optical apparatus
US4500208A (en) Apparatus for seeking faults in wide material webs
US4116527A (en) Device for concentrating light from a linear field on to a receiver
US4227091A (en) Optical monitoring apparatus
US4295743A (en) Apparatus for determining faults in strip material
US4108533A (en) Apparatus for combining light emanating from a linear scanning field
DE3737632C2 (fr)
DE19511990C2 (de) Messvorrichtung zum Messen von Transversalgeschwindigkeit und Länge eines Messobjekts
EP0119618B1 (fr) Appareil optique pour la mesure de la transmission
GB2054835A (en) Scanning Apparatus for Flaw Detection
DE3408106A1 (de) Optischer rauheits-scanner
US4070114A (en) Detector optics for use in fabric inspection
JPH04110707A (ja) 三次元形状計測装置
GB2129932A (en) Position and/or dimensions of objects

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19810107

AK Designated contracting states

Designated state(s): FR GB IT

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Designated state(s): FR GB IT

ITF It: translation for a ep patent filed

Owner name: BARZANO' E ZANARDO MILANO S.P.A.

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Designated state(s): FR GB IT

ET Fr: translation filed
PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed
PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19890107

Year of fee payment: 9

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 19890117

Year of fee payment: 9

ITTA It: last paid annual fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: GB

Effective date: 19900107

GBPC Gb: european patent ceased through non-payment of renewal fee
PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Effective date: 19900928

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST